Transmission Control Protocol (TCP) is an underlying connection protocol that is typically used for all types of network communication. A route is essentially the mapping of an IP address to an egress port of a router. Different network routers set up connections with their peer routers using operating systems, for example Border Gateway Protocol (BGP) over TCP or OSPF (Open Shortest Path First) over Internet Protocol (IP) to determine that they get route information from their peers, allowing them to construct essentially an internal map of the network and to select the route that they should use, as well as verification that their peers are operating correctly. This is accomplished by sending various keep-alive packets back and forth to make sure that their peers are still correctly functioning. Routes are used internally within a router, for example a Master Control Processor (MCP) communicates through an Ethernet control network (CNET) within a router with the shelf control processors, each of which have individual IP addresses. Processes including routing applications, for example Dynamic Routing Protocol (DRP), run on these operating systems. Sockets are end points of communication associated with a process. A particular process can have more than one socket.
In a router with a large number of ports, for example 320 ports, that communicates with peer routers, it is advantageous to subdivide that single large router logically into several smaller virtual routers, each of which can be individually configured. There can be separate departments in a large company, or an Internet provider wanting to partition a large router among clients, for example for security reasons. However, previous implementations of subdividing routers having large numbers of ports have been cumbersome.